The present invention is generally directed to shredders and, more specifically, to a safety feature(s) for shredders.
Conventional shredders can have three operating modes. The first operating mode is an “off” mode in which the shredder blades are deactivated and no shredding of material can take place. The second operating mode is an “on” mode in which the shredder blades continually rotate to shred any material inserted into the shredder. The third operating mode is an “automatic” mode in which the shredder blades are automatically activated when the shredder detects that material is being inserted into the shredder. The “automatic” mode is advantageous in that material can be sporadically shredded without having to continually turn the shredder on and off. This makes it easy to open mail and immediately shred those items which are unneeded and may contain personal information.
However, the use of shredders in “automatic” mode can be problematic. The shredder can unintentionally be left in “automatic” mode after all shredding is completed since the lack of noise generated from shredder blade movement may result in a user forgetting that the shredder is not off. A shredder left in “automatic” mode for an extended period of time can present a safety hazard to the original or new users who are unaware that the shredder is only waiting to detect the insertion of material therein to activate its shredder blades. This can result in fingers or clothing being positioned near or inside the shredder slot while the shredder is not off which may lead to serious injury. The problem is further exacerbated when little children approach an unmonitored shredder left in “automatic” mode. Children are more prone to insertion of clothing and/or body parts into a shredder slot and are very likely to believe that the shredder is off. The impact of shredder blades on a young child can be devastating.
Safety hazards are also present in those shredders operating in “on” mode. These problems result from the shredder's ability to be left in “on” mode while unattended and also from portions of one's body being inserted in the shredder's material feed slot while the shredder is in the “on” mode. This also creates a hazard to which children are especially susceptible.
One solution to this problem is to provide a control circuit with nodes that are present along the outer surface of the shredder housing that relies on the static charge of a person to be detected by the control circuit through the nodes. When the human charge is detected, the control circuit turns the shredder off. This is problematic for a few reasons. When feeding paper into the shredder, a user's hand frequently briefly contacts enough nodes to cause the shredder to not function reliably. Additionally, when a person's skin is dry and/or the environment is humid, the sensitivity of the control circuit is reduced due to its reliance on detecting the latent static charge in a person. This can result in the control circuit failing to detect a portion of a person's body and allowing the shredder blades to cause serious injury. Additionally, metallic and/or magnetic objects such as credit cards and or metallic decorative inks can result in the shredder accidentally stopping due to mistaking the metallic and/or magnetic material as a human body part.
It would be advantageous to provide a shredder that provides increased safety for users and others that come into contact with the shredder.